Cirsium japonicum DC is listed as a health food in China used for cooling blood and hemostasis. The aim of this study was to identify its active components with anti-inflammation activity. C. japonicum was extract with 70% ethanol, and then loaded on a macroporous resin column chromatography to get five fractions. Results showed that fraction CJ-50 exhibited the best anti-inflammation effect. Six compounds, luteolin-7-O-β-D-glucuronide (LG), luteolin-7-O-β-D-glucuronide methyl ester, apigenin-7-O-β-D-glucuronide (AG), linarin, apigenin-7-O-β-D-glucuronide methyl ester, and pectolinarin, were isolated and identified from the fraction. The six flavonoid compounds exhibited different degree of anti-inflammatory activity, among which LG and AG showed stronger activity than others. Further research showed that LG can inhibit the NO and pro-inflammatory cytokines production, likely resulting from inhibiting the phosphorylation of JNK. Taken together, these results suggest that LG may be therapeutic candidate for anti-inflammation activity of C. japonicum as well as a dietary complement for health promotion.